Investigate of O-emission mechanism from YSZ/metal surface into gas phase

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Radical reactions play important roles in combustion process and catalytic process. However, there are few methods, which produce radicals effectively as well as selectively. We approach this problem in the view of developing new radicals generator. Yttria Stabilized Zirconia (YSZ) is often used as an oxygen sensor and/or a solid electrolyte because of its oxygen anion (0^2) conducting characteristics. Desorption of oxygen anion radicals from the YSZ can be expected in a low electric field of 100- 200V/cm at around 400-5000ﾟC.The main purpose of our research is to determine the amount of oxygen species and estimate the rate-determining step by use of QMS (Quadrupole mass spectroscopy) . Only 0 was detected as oxygen anion species. Experimental results showed that the desorption process of oxygen anion species from the anode electrode of the YSZ was most dominant factor in our process. The activation energy of oxygen anion desorption was estimated to be 80-lOOkJ/mol in the case that 100-200V/cm was applied.This research also focus on metal catalysts(Ag, Pt) which favor oxygen adsorption, because the low electric field of lOOV/cm may release the adsorbed oxygen as oxygen anion radicals. A mass spectrum of anion species contained both MN=(O) and MN=32 (0_2) . Our results indicate that the metal catalysts have the possibility of generating oxygen anion radicals